Shuttle device having a rotating hook for a sewing machine



M. FRESARD Nov. 16, 1965 SHUTTLE DEVICE HAVING A ROTATING HOOK FOR A SEWING MACHINE Filed Sept. 5, 1965 Ml/f/VTOQ flame; Flees/Mp 3y W United States Patent 3,217,678 SHUTTLE DEVICE HAVING A ROTATING HOGK FOR A SEWING MACHINE Marcel Fresard, Petit-Lancy, Geneva, Switzerland, assignor to Meiina S.A., Fribourg, Switzerland, a corporation of Switzeriand Filed Sept. 5, 1363, Ser. No. 306,738 Claims priority, application Switzerland, Sept. 14, 1962, 10,943/62 Claims. (Cl. 112184) The present invention concerns a shuttle device having a rotating hook for a sewing machine, comprising a rotatable race secured to a vertical driving shaft, the hook being formed on the edge of this race which presents interiorly a support member for a spool adapted to pay out a lower thread, a loop of an upper thread being adapted to be drawn by a needle which is displaced parallel to the axis of the race and tangentially to the hook, an abutment mechanism retaining the spool support in position against any entrainment by the hook, this mechanism comprising two abutments carried by the spool support and disposed on both sides of the path of the needle, an escapement oscillating under the action of a rotatable cam presenting two beaks co-operating respectively with two abutments, so that one of the beaks is always in contact with one of the abutments, the oscillation of this escapement permitting a space to be left alternatively between each pair of cooperating beaks and abutments, for the passage of the loop of the upper thread.

There are already known shuttle devices having rotating hooks provided with an abutment mechanism using an escapement oscillating under the action of a rotatable cam. However, in general, in these known devices as described in US. Patent No. 2,505,523, the oscillating axis of the escapement is not parallel to the axis of the race, or of the hook. There ensues difficulties in adjustment to ensure that each retaining beak of the escapement works in a perfect manner with the abutment which it must maintain in place. Machines provided with these known devices are very sensitive to being put out of order which is always possible after a certain time of use of the machine or after Wear of certain parts, clogging by dust or thread debris. An object of the present invention is to remedy the abovementioned inconveniences.

According to the present invention a shuttle device is characterized in that the oscillating axis of the escapement is parallel to that of the axis of rotation of the hook, the control cam of the escapement being secured to the driving shaft of the hook and disposed below the race, the escapement comprising a plate guided horizontally below the race and against which the cam operates, this plate presenting two upwardly folded extensions and each end of which constitutes one of the two beaks, the oscillating axis of the escapement being situated in a central position between the two beaks, this axis being parallel to that of the cam, in such a manner as to avoid all oscillating movements of the spool support.

The invention will now be described further, by way of example, with reference to the accompanying drawings, in which:

FIGURE 1 is a front elevation of the shuttle device, constructed in accordance with the invention, viewed in the direction of use of the sewing machine;

FIGURE 2 is a corresponding side elevation;

FIGURE 3 is a plan of the device in a particular functioning position;

FIGURE 4 is a fragmentary plan similar to FIGURE 3, showing the device in a different functioning position; and

FIGURE 5 is a plan view of the control mechanism for the escapement.

A shuttle device having a rotating hook for a sewing machine comprises a rotatable outer casing 1 with a hook 3,217,678 Patented Nov. 16, 1965 7 thereon secured to a driving shaft 2 journalled in a bearing (not shown) of a frame 3 of the sewing machine. The axis of rotation of this shaft 2 is vertical. A pinion 4 is machined on the lower part of this shaft 2. This pinion meshes with a tangent screw 5 driven by a horizontal shaft 6 disposed longitudinally in the lower part of the sewing machine, respectively in the free arm thereof.

A member 8 is disposed inside this casing 1. This member 8 is adapted to serve as a support for a spool 9 adapted to pay out a lower thread 10. The spool is mounted by well known means in the casing as described in US. Patent No. 2,673,541. A loop of an upper thread 11 is adapted to be drawn by a needle 12 of the machine, which needle is displaced parallel to the axis of rotation of the casing 1 and tangentially to the hook 7.

An abutment mechanism is adapted to retain the spool support 8 in position against any rotating movement by the hook 7 or by the casing 1. To this end, the mechanism comprises two abutments 13 and 14 respectively formed on a plate 15 connected by screws 16 on an upper capsule 17 of the spool support 8. These two abutments 13, 14 must be disposed on both sides of the path of the needle 12. The task which consists in maintaining these two abutments 13 and 14 in a determined position falls to an escapement 18 presenting two retaining beaks 19 and 20 respectively. The beak 19 is adapted to co-operate with the abutment 13 (FIGURE 3) whilst the beak 20 is adapted to co-operate with the abutment 14 (FIGURE 4).

This escapement 18 is constituted by a plate presenting a main member 21 guided horizontally below the casing 1. This plate 21 oscillates along an axis 22 carried by a plate 23, generally called a saddle. The plate 21 has an opening 24 therein with two parallel edges 25 and 26. A control cam 28 constituted in this particular case, by an eccentric, is engaged in the opening 24, in such a manner as to be found in contact with the two parallel edges 25 and 26. This eccentric 27 is, preferably constituted in a synthetic material having a low coefficient of friction, such as nylon for example; it is secured to the shaft 2 which moves it simultaneously with the race and the hook 7.

It is to be understood without further explanation that in the course of the rotating movements of the eccentric 27, that plate 21 is driven in oscillating movements around the axis 22.

The guiding of the plate 21 is effective thanks to a guide 28, preferably of synthetic material having a low coefficient of friction. The oscillating axis 22 of the escapement 18 is situated in a central position between the two beaks 19 and 20, and this axis being parallel to that of the eccentric 27. The guide 28 is disposed for guiding the part of the plate 21 which is furthest away from the oscillating axis 22. Moreover, guide plates 29, preferably likewise of synthetic material having a low coefiicient of friction, are fixed in an intermediate position on the plate 21 between the guide 28 and the oscillating axis 22 in the proximity of the parallel edges 25 and 26 of the opening 24. These plates 29 rest on the plate or saddle 23 and slide back and forth thereon, as shown in FIG. 1.

As clearly shown in FIGURE 2 the beaks 19 and 20 are formed at the ends of two upwardly folded extensions 30 and 31 of the plate 21. The working faces of the beaks 19 and 20, that is to say, their faces adapted to enter into contact with the abutments 13 and 14 respectively, present a cylindrical curvature centered on the oscillating axis 22. It is to be noted that the working faces of the abutments 13 and 14 likewise present a similar curvature, thus avoiding oscillations of the abutments 13 and 14 secured to the plate 15.

As can be seen from a study of FIGURES 3 and 4, at the end of the oscillating movement in the clockwise direction of the escapement 18, the beak 20 moves away from the abutment 14 and a free space I appears between these two parts. Likewise, at the end of the oscillating movement in the anti-clockwise direction and as shown in FIGURE 5 in broken lines, the beak 19 of the escapement 18 moves away from the abutment 13 (FIGURE 4) and a space K appears between the parts 13 and 19.

The functioning of the shuttle device having a rotating hook described above is effected in the following manner:

First of all it is to be noted that the hook 7 effects two complete revolutions for each stitch, that is to say for each prick of the needle 12. This is well known and is described in US. Patent No. 2,505,523. At the beginning of the prick of the needle 12, this draws the upper thread 11 between the abutments 13 and 14 up to a level lower than that of the hook 7. At the moment where the lifting of the needle starts (FIGURE 1), one of the strands of the upper thread 11 forms a loop 32 which appears in the path of the hook '7 which takes it up as soon as it arrives at its height. Subsequently, the hook 7 drives this loop around the spool 9 and thus around the lower thread 10. The beginning of the drawing of the loop 32 around the spool 9 is permitted by the opening of the space K which is formed between the abutment 13 and the beak 19 (FIGURE 4). Subsequently the return of the loop 32 after its revolution around the spool 9 in the clockwise direction, is rendered possible by the opening I which occurs between the abutment 14 and the beak 2t) and the end of the oscillating movement in one direction of the escapement 18. Thus, the passage of the loop 32 of the upper thread 11 is effected freely between the abutments 13 and 14 and their respective retaining beaks 19 and 20 without the passage of the loop 32 of the upper thread 11 provoking any vibration of the spool support 8. After the return of the loop 32 between the abutments 13 and 14 the needle 12 has already withdrawn upwardly and the thread 11 is likewise drawn upwardly by a thread pulling device, the stitch being finished by the knotting of the upper thread 11 to the lower thread 10 in the material.

The great advantage of the shuttle device described above is that it does not necessitate any adjustment. In fact, the parts which constitute it, once machined with precision, can be assembled in being perfectly sure that the same conditions of functioning are repeated in each assembly of shuttle device in the course of manufacture. The drawings show that the device is of simple and compact construction which greatly ficilitates its mounting, especially in sewing machines having fre arms where the available space is restricted.

Finally the parts of the device sensitive to wear being, preferably, made in synthetic material having a low coefficient of friction, no Wear of the device is noted after long use of the machine.

I claim:

1. In a sewing machine having a needle, an upper thread supply adapted to be paid out by a vertically reciprocal needle and a lower thread supply adapted to be paid out by a spool, a shuttle device comprising a vertical driving hook shaft, a rotatable casing having a raceway secured to said shaft, a hook formed on an edge of said casing, a spool support member arranged interiorly of said casing for supporting said spool which spool is removably disposed in said casing, a control cam secured to said hook shaft below said casing, said needle reciprocating in a path parallel to the axis of said casing and tangentially to said hook and forming depending loops at predetermined intervals, and an abutment mechanism, retaining said spool support member in position against any movement by said hook, comprising two abutments carried by said spool support member, one disposed on each side of the path of said needle and an oscillating escapement comprising a plate for actuation by said control cam and means guiding said escapement horizontally below said casing, said plate having two upwardly folded extensions, each extension forming a beak, each of said beaks cooperating respectively with said abutments in such a manner that one of said beaks is always in contact with one of said abutments, the oscillation of said escapement permitting a space to be left alternatively between each pair of cooperating beaks and abutments for the passage of said loop, said escapement having an axis of oscillation disposed parallel to the axis of rotation of said hook and parallel to the vertical hook shaft and cam axis, said oscillating axis of said escapement being disposed centrally between said two beaks, whereby oscillating movements of said spool support are avoided.

2. A. device according to claim 1, wherein said cam actuated plate has an opening formed therein with two parallel edges, said control cam being an eccentric disposed in said opening and in contact with said two parallel edges.

3. The device of claim 2 wherein said guide means are made of synthetic material having a low coefiicient of friction for guiding said plate.

4. The device of claim 2 wherein said guide means consist of a first guide member disposed adjacent the part of said plate opposite said axis of oscillation, and second and third guide members disposed between said first guide member and said axis of oscillation, and disposed adjacent said parallel edges of said plate, said second and third guide members :being fixed to said plate.

5. The device of claim 4 wherein a support plate is provided extending perpendicular to the axis of rotation of said hook and said second and third guide members are disposed for sliding upon the surface of said support plate.

References Cited by the Applicant UNITED STATES PATENTS 32,219,470 10/ 1940 Carlson 112232 2,236,830 4/1941 Myers 112l84 2,505,523 4/1950 Robert 112-184 2,673,541 3/1954 Biesemeyer 112-232 X 2,822,773 2/ 1958 Ivanko 112.232

FOREIGN PATENTS 289,962 7/ 1953 Switzerland.

JORDAN FRANKLIN, Primary Examiner, 

1. IN A SEWING MACHINE HAVING A NEEDLE, AN UPPER THREAD SUPPLY ADAPTED TO BE PAID OUT BY A VERTICALLY RECIPROCAL NEEDLE AND A LOWER THREAD SUPPLY ADAPTED TO BE PAID OUT BY A SPOOL, A SHUTTLE DEVICE COMPRISING A VERTICAL DRIVING HOOK SHAFT, A ROTATABLE CASING HAVING A RACEWAY SECURED TO SAID SHAFT, A HOOK FORMED ON AN EDGE OF SAID CASING, A SPOOL SUPPORT MEMBER ARRANGED INTERIORLY OF SAID CASING FOR SUPPORTING SAID SPOOL WHICH SPOOL IS REMOVABLY DISPOSED IN SAID CASING, A CONTROL CAM SECURED TO SAID HOOK SHAFT BELOW SAID CASING, SAID NEEDLE RECIPROCATING IN A PATH PARALLEL TO THE AXIS OF SAID CASING AND TANGENTIALLY TO SAID HOOK AND FORMING DEPENDING LOOPS AT PREDETERMINED INTERVALS, AND AN ABUTMENT MECHANISM, RETAINING SAID SPOOL SUPPORT MEMBER IN POSITION AGAINST ANY MOVEMENT BY SAID HOOK, COMPRISING TWO ABUTMENTS CARRIED BY SAID SPOOL SUPPORT MEMBER, ONE DISPOSED ON EACH SIDE OF THE PATH OF SAID NEEDLE AND AN OSCILLATING ESCAPEMENT COMPRISING A PLATE FOR ACTUATION BY SAID CONTROL CAM AND MEANS GUIDING SAID ESCAPEMENT HORIZONTALLY BELOW SAID CASING, SAID PLATE HAVING TWO UPWARDLY FOLDED EXTENSIONS, EACH EXTENSION FORMING A BEAK, EACH OF SAID BEAKS COOPERATING RESPECTIVELY WITH SAID ABUTMENTS IN SUCH A MANNER THAT ONE OF SAID BEAKS IS ALWAYS IN CONTACT WITH ONE OF SAID ABUTMENTS, THE OSCILLATION OF SAID ESCAPEMENT PERMITTING A SPACE TO BE LEFT ALTERNATIVELY BETWEEN EACH PAIR OF COOPERATING BEAKS AND ABUTMENTS FOR THE PASSAGE OF SAID LOOP, SAID ESCAPEMENT HAVING AN AXIS OF OSCILLATION DISPOSED PARALLEL TO THE AXIS OF ROTATION OF SAID HOOK AND PARALLEL TO THE VERTICAL HOOK SHAFT AND CAM AXIS, SAID OSCILLATING AXIS OF SAID ESCAPEMENT BEING DISPOSED CENTRALLY BETWEEN SAID TWO BEAKS, WHEREBY OSCILLATING MOVEMENTS OF SAID SPOOL SUPPORT ARE AVOIDED. 